have sth. at/on the tip of one's tongue

1. 差一点就想起某事

I have her name on the tip of my tongue.

她的名字就在我嘴边, 却说不出来。

have sth. at the tip of one's fingers

1. 手头就有某物

He always has some money at the tip of his fingers.

他手头总有些钱。